When I was involved in a Camaro business in the '80s we used to go to the Pomona CA swap meet a couple times a year. One of the locals had a small business converting vinyl-rim NK1 wheels to real wood. He would strip off the vinyl, replace it with wood and re-finish. Probably was not worth the work.

I do not have any personal experience, but I understand that Inland, the company that made the wheels, made many prototypes that where given to execs and sales reps. A guy over on sYc site had a few "one offs" for sale. A search should be able to find some example pics.